S4 Occasional vibration

[rizzini7]

I'm occasionally getting a vibration/judder that can be felt in seat. Don't feel it in the peddles or steering. Seems to happen at 50-60 when off the throttle and will stop by pressing clutch or accelerating.
Been doing it a while but hasn't got any worse. Tyres have recently been changed and was doing it beforehand.

Cars 2010 s4 avant 6sp manual 58k
with full ads (dampers, diff etc..) and revo stage one, full scorpion exhaust, awe carbon flo intake and power flex poly transmission insert.

Could it be as simple as the exhaust resonating? Or from gb insert


Sent from my iPhone using Tapatalk

 

[CrypticS3]

Is there any noise to go with the vibration? What frequency is the vibration? Does it feel like it matches the engine speed or the speed the car is travelling at? Does it only appear when the transmission isn't loaded or does it just reduce? When was the last time you got the geometry checked? Can you feel it through the gearstick? There are a lot of things that can cause a vibration so need more info before we can properly speculate. Basically the list goes like this so far.

First, because it's so simple it's easily missed..... Are the wheel bolts torqued correctly?

Wheel bearing - Rear
Wheel Balancing - Rear (I know you had new tires but you could have thrown a weight)
CV Joint
Bent Driveshaft (unlikely but still possible)
Propshaft Bushings
Diff bushings
Gearbox Bushings
Flywheel issue
Clutch issue
Busted engine mount
Could be a loose/broken bolt.

As you can see there is quite a lot there and possibly more so again more info is needed to rule out items on this list.

 

[xpoweruk]

Can you replicate it with revs ? or is it specifically only at a set speed ?

 

[rizzini7]

Typically I'd been playing around on the way up to Scotland yesterday to see what triggered and stopped it. But, totally forgot half of it by last night. Now stuck on small single track hilly roads for a few days but will try and do some more investigations. Thanks for replying so far.

There's no noise with it I can hear. And just seems to be felt through the seat (my backside )
I've had the wheels balanced before new tyres and when they fitted 4 new tyres. Also had 4 wheel alignment done with the new tyres.

Doesn't happen all the time, at around 50mph (will check revs) doesn't seem to matter what gear either. Happens when coasting and pressing the clutch in or the throttle it stops.

Should says it's defiantly a vibration not a judder like I put.






Sent from my iPad using Tapatalk

 

[rum4mo]

"Scotland" and "single track roads" ? You are not heading up North to round about Applecross and that famous pass to get there are you? If so watch out for roadworks signs, I missed one there once and so did my parking sensors, that cost a bit to tidy up!!

Edit:- by the way, you are always going to hear funny noises etc when away from your home area, my latest funny noise, happened 2 weeks ago while driving to the airport to park and fly away on holiday, that funny, it was only the late 2009 Ibiza I was using, was the start of a broken front spring, then the broken part escaped - I went back to check that that was what it was! Still the car did its work and got us to and from the airport, next job to do!

 

[rizzini7]

"Scotland" and "single track roads" ? You are not heading up North to round about Applecross and that famous pass to get there are you? If so watch out for roadworks signs, I missed one there once and so did my parking sensors, that cost a bit to tidy up!!

Edit:- by the way, you are always going to hear funny noises etc when away from your home area, my latest funny noise, happened 2 weeks ago while driving to the airport to park and fly away on holiday, that funny, it was only the late 2009 Ibiza I was using, was the start of a broken front spring, then the broken part escaped - I went back to check that that was what it was! Still the car did its work and got us to and from the airport, next job to do!

We're up at Durness (Cape Wrath) the vibrations been there several months. Not a big issue at the moment. But, thought I should investigate. Doesn't seem to or got any worse in that time.


Sent from my iPhone using Tapatalk

 

[CrypticS3]

Going by what you've said the first thing I'd do is remove the Box Insert. From there I'd have a good look at all the driveline bushes whilst you're under there. Take it for a drive and report back.

 

[rizzini7]

Now home, after a long drive. I haven't had a chance to get my mate to look over the car. (It's safer I don't get involved )

However, seems I was wrong the vibration is at around 2k revs when off throttle in any gear. Not a set speed. And once warmed up.
It also feels similar to the vibration I get from the exhaust when revving the car out of gear.
I've never had the exhaust rechecked since it was fitted. It's a tight fit

Will probably get my mate to remove the gb insert just to check and give the underside a good look over. If it turns out to be just the insert i can live with it and will get put back in.
I'm just more concerned about it being the sports diff or something like that ££££

Thanks for the help. Sorry for my lack of knowledge


Sent from my iPad using Tapatalk